<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    
</body>
<script>

    // console.log( NaN > 1 )
    // console.log( NaN < 1 )
    // console.log( NaN === 1 )
    // console.log( NaN === NaN );
    // var a = NaN;
    // console.log( a === a );

    // console.log( isNaN( NaN ) )

    // console.log( isNaN( 345 ) )
    
    // console.log( isNaN( "hello" ) )
    // console.log( isNaN( "345" ) )
    // console.log( isNaN( true ) )
    // console.log( isNaN( false ) )


    // console.log( undefined == null )
    // console.log( undefined == NaN )
    // console.log( null == NaN )


    console.log( 0.1 + 0.2 );
    console.log( Number((0.1 + 0.7).toFixed(8)) === 0.8 );
    console.log( 0.1 + 0.2 === 0.3 );







    
</script>
</html>